March 12 (Reuters) - The United States issued a 30-day license for countries to buy Russian oil and petroleum products currently stranded at sea in what Treasury Secretary Scott Bessent said was a step to stabilize global energy markets roiled by the war on Iran.

Bessent, in a statement on X released hours after benchmark oil prices shot above $100 a barrel to their highest in nearly four years, said the measure would not provide significant financial benefit to the Russian government.

The announcement comes a day after the U.S. Energy Department said that the U.S. would be releasing 172 million barrels of oil from the strategic petroleum reserve in an effort to curb sky-rocketing oil prices in the wake of the war in Iran. That release was part of a broader commitment by the 32-nation International Energy Agency to release 400 million barrels of oil.

Thursday's license, which authorizes the delivery and sale of Russian crude oil and petroleum products loaded on vessels as of March 12, will remain valid through midnight Washington time on April 11, according to the text of the license posted on the Treasury Department's website.

The U.S. Treasury previously had issued a 30-day waiver on March 5 specifically for India, allowing New Delhi to buy Russian oil stuck at sea.

Among measures to tame energy prices, President Donald Trump has already ordered the U.S. International Development Finance Corporation to provide political risk insurance and financial guarantees for maritime trade in the Gulf and said the U.S. Navy could escort ships in the region.

U.S. and Israeli strikes on Iran and the subsequent response by Tehran have widened regional tensions and paralyzed shipping through the Strait of Hormuz, disrupting vital Middle East oil and gas flows and sending energy prices higher.

Raising the stakes for the global economy, Iran's Islamic Revolutionary Guard Corps says it will block oil shipments from the Gulf unless the U.S. and Israeli attacks cease.